Congenital hypoplasia of the internal carotid artery.

A newborn presented at 14 hrs of age with right sided clonic seizures and shrill cry. Magnetic Resonance Imaging of the brain showed left cerebral hemiatrophy with cystic changes in left fronto-parietal lobe and parasylvian region. The Magnetic Resonance Angiography revealed hypoplasia of left supraclinoid Internal Carotid Artery and hypoplasia and irregularity of vessel wall affecting the left Middle Cerebral Artery. Such an early presentation of this rare disorder has not been reported previously. Recognition of this anomaly has important implications during carotid and trans-sphenoidal surgery, in thromboembolic disease, and in the surveillance and detection of associated cerebral aneurysms.